Electric fan conversion

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E30 Zone Newbie
E30 Zone Newbie
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Joined: Wed Dec 12, 2018 11:38 pm

Thu May 02, 2019 10:54 pm

Hi, my viscous fan is starting to fail and pretty useless. Im going to change to electric fan with a thermostat switch to engage it. i've noticed there are several different temp switches available that kick in at various temperatures. My question.. what temperature should the fan come on at? its an m20b25 engine.
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E30 Zone Team Member
E30 Zone Team Member
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Joined: Mon Jan 10, 2005 11:00 pm

Thu May 02, 2019 11:07 pm

Temp switch should be set to switch on at slightly more than the running temp. of the engine, which for a M20B25 is 80 degrees, so around 85 degrees.
I'd think twice about the conversion, though. An electric fan set up is MUCH less reliable than a viscous coupling.
Old Skooler
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Fri May 03, 2019 7:54 am

it all depends on whether you want a single & double speed fan & if it will be a pusher/puller fan.

i installed mine (pusher fan from a 2.5 tds omega) using a 80/88 two pin switch in the side of the radiator & used a 4 pin fused relay from a revotec fitting kit, it's wired up as a single (high) speed, mainly as a back up.

but for the cost of all the parts a viscous coupling can work out cheaper. & rock auto in th states do one's from £30 up to £50.
if it's got t*ts or wheels it's bound to be trouble...............prove me wrong.
getting oral sex off an ugly person is like rock climbing.....don't look down ;)
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Joined: Fri Oct 23, 2015 10:00 pm

Fri May 03, 2019 11:12 am

I agree with Brian, electric fans are less reliable, I remember on a historic rally that went down to Morocco, someone being in real trouble when his Kenlowe disintegrated. If you must go electric put in a pair so that you have a back-up.
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